Chicago Marathon
Race Day Weather
Cool start, variable winds ahead
Runners will face a temperature increase from 55°F at the start to 66°F by the finish, with humidity at 60%. Wind will shift from a tailwind to headwinds through various segments, peaking at 12 mph. Runners should prepare for tough stretches with headwinds from miles 2-14 and mile 21, while taking advantage of tailwinds from miles 1-2 and 24-27 for faster pacing.
Pace Calculator
Get forecast alerts for Chicago Marathon
We'll text or email you when the forecast shifts — so you can adjust gear, pacing, and strategy. Max one per day.
Get your personalized Chicago Marathon race plan
Weather-adjusted pacing, per-mile terrain splits, fueling timeline with aid stations, packing checklist, carb tracker, spectator guide — all personalized to your goal and race-day conditions.
Race Info
The Chicago Marathon is a marathon (long-distance foot race) held every October in Chicago, Illinois. It is one of the six World Marathon Majors. Thus, it is also a World Athletics Label Road Race. The Chicago Marathon is the fourth-largest race by number of finishers worldwide. Wikipedia
